Retractable rig for operating hatch covers



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Sept. 9, 1969 u. J. BEAS RETRACTABLE RIG FOR OPERATING HATCH COVERSFiled Dec. 26, 1967 5 Sheets-Sheet l mvsmok. unamv J- BEAS ATTORNEYS.

Sept. 9, 1969 u. J. BEAS RETRACTABLE RIG FOR OPERATING HATCH COVERS' 5Sheets-Sheet 2 Filed Dec. 26, 1967 INVENTOR. URBAN .1. 5545 BY 9{ &7

ATTOQNEYS.

Sept. 9, 1969 u. J. BEAS RETRACTABLE RIG FOR OPERATING HATCH COVERSFiled Dec. 26, 1967 5 Sheets-Sheet I u /////////rrI// FIGS FIG. 7

FIG. 6

INVENTOR. URBAN J 85115 7 ATTORNEYS.

Sept. 9, 1969 u. J. BEAS 3,465,807

RETRACTABLE RIG FOR OPERATING HATCH COVERS 5 Sheets-Sheet 4 Filed Dec.26, 1967 FIG. 8

I/VVE'IVTUZ URBAN J. BEAS Sept. 9, 1969 u. J. BEAS 3,465,807

RETRACTABLE RIG FOR OPERATING HATCH COVERS Filed Dec. 26, 1967 5Sheets-Sheet 2,-

A T TORNE Y5 Q o 2 L 5. i 3 8w: E

g 1 1 $2 $31 M Z U 1 81 mvv aw 3v Q\ L. W. O a

United States Patent U.S. Cl. 160-188 18 Claims ABSTRACT OF THEDISCLOSURE A retractable rig for operating hatch covers on cargovessels, barges, or the like. The rig comprises a boom and linkage whichare retractable when not in use. In a preferred embodiment, the rig isretractable into a channel in the hatch cover such that in the retractedposition, the rig does not project above the surface of the hatch cover.A winch is provided to operate the boom and linkage and the winch isalso preferably retractable below the surface of the hatch cover.Increased mechanical advantage is obtained by locating the effectiveaxis of rotation of the boom forward of the axis of rotation of thehatch cover and by using a rope and pulley arrange ment as the linkagebetween the winch and boom.

This application is a continuation-in-part of Ser. No. 608,870, filedJan. 12, 1967 and now abandoned.

This invention relates to a new and improved rig for operating hatchcovers, and more particularly to a new and improved retractable rig foropening and closing hatch covers on cargo vsesels, barges, or the like.

Cargo-carrying vessels such as cargo ships, barges and the like, arecommonly equipped with a hatch cover comprising a single sectionpivotally mounted along one edge of the hatchway, or a plurality ofsuccessive sections pivotally interconnected to comprise anaccordion-like row with the end-most, or first, section pivotallyconnected on an edge of the hatchway, so that the hatchway may be openedby folding the sections against each other in succession. Inapplications, such as on cargo vessels, where space is not as critical,the hatch cover may be opened and closed by means of one of severalsystems. One such system utilizes motors associated with the hatch coveritself, whereby the hatch cover is opened and closed by energizing themotors from an electrical source of power located on the vessel. Anothersuch system utilizes a power winch mounted on the deck of the vesselhaving a rope or the like secured to the hatch cover. Where the winch isnot used exclusively to open and close the hatch cover, it is necessaryto manually secure a rope to the cover each time it is opened. A furthersystem utilizes the hoist associated with the power boom. All of theabove systems generally utilize electrical power. In applications whereelectrical power is not available, manually operable winches permanentlymounted on the deck may be provided. These manually operated winchessuffered the disadvantage that mechanical advantage could only be obstantial height above the deck.

Great interest is presently being shown in containerized cargo vesselswherein a plurality of barges are stacked one upon the other within thehold of the vessel. In order to maximize the number of barges that maybe vertically stacked within a given hold depth, it is desirable thatthe vertical depth of an individual barge be utilized to the fullestextent for the storing of cargo. It is also desirable that the uppersurface of the barge be as free as possible from projections or thelike. It is also desirable to provide 3,465,807 Patented Sept. 9, 1969 arig for opening and closing the hatch covers on the barge which iseither operable manually or automatically by means of a suitable powermeans.

According to the present invention, a rig for opening and closing hatchcovers is provided which is especially adapted for use in applicationswhere space is critical such as barges stacked within a containerizedcargo vessel. In general, the rig of the present invention comprises aretractable boom and linkage which are adapted to be stowedsubstantially horizontally when not in use. In a preferred embodiment,the boom and linkage are stowed within the hatch cover when not in useand a winch, operable either manually or automatically, is provided,associated with the boom. In such case, the winch is also preferablyretractable and is stowed below the plane of the upper surface of thehatch cover. A self-operating energy accumulator device may also beprovided to achieve greater mechanical advantage in opening the hatchcover. Further mechanical advantage may be obtained by locating theeffective axis of rotation of the boom in advance of the axis ofrotation of the hatch cover and by using a rope and pulley arrangementas the linkage between the boom and the winch.

It is thus an object of the present invention to provide a new andimproved rig for operating hatch covers which may be simply andefiiciently operated.

It is a further object of the present invention to provide a new andimproved rig for operating hatch covers which is easily extended orretracted and which occupies a minimum amount of space when in theretracted position.

It is yet another object of the present invention to provide a new andimproved rig for operating hatch covers which may be operated eithermanually or automatically.

It is still another object of the present invention to provide a new andimproved rig for operating hatch covers which, in conjunction with anenergy accumulator device, is adapted to permit easy opening ofcomparatively heavy hatch covers.

It is also an object of the present invention to provide a new andimproved rig for operating hatch covers which may be stored within andlocked within a hatch cover in the open position when the hatch coverhas been opened by external means.

Other and further objects of the present invention will be evident tothose skilled in the art from the following description and drawingswherein:

FIG. 1 is a plan view of a preferred embodiment of the rig of thepresent invention in association with a hatch cover mounted on a barge;

FIG. 2 is a side elevational view of the embodiment of FIG. 1;

FIG. 3 is a side elevational view showing one part of the hatch coverretracted and the other part of the hatch cover extended but with therig of FIG. 1 partially extended;

FIG. 4 is a partially sectional elevational view taken along line 44 ofFIG. 1;

FIG. 5 is a partially sectional elevational view taken line 5-5 of FIG.1;

FIG. 6 is a partially sectional elevational view taken along line 66 ofFIG. 5;

FIG. 7 is a partially sectional elevational view taken along line 77 ofFIG. 5;

FIGURES 8 and 8a are side elevational views of another embodiment of therig of the present invention;

FIG. 9 is a partially sectional plan view of the rig of FIGS. 8 and 8a;and

FIG. 10 is a partially sectional elevational view taken along line10-10' of FIG. 9.

Referring now to the figures, there is shown in FIGS. 1 and 2 a hatchcover generally connoted by the numeral 10 comprised of a plurality ofsections 12, 14, 16 and 18. Sections 12 and 14 are pivotally connectedtogether by hinges 20, as are sections 16 and 18. Paired sections 12, 14and 16, 18 are respectively adapted to fold to a vertical position tothe left and to the right when hatch cover 10 is fully opened.

Hatch cover 10 is pivotally mounted on coaming 22 of barge 26 by meansof arms 24 rigidly connected to sections 12 and 18, arms 24, in turn,being pivotally mounted on brackets 27 rigidly secured to coaming 22.Energy accumulator devices 28, to be described in greater detailhereinafter, are also provided.

The opening and closing of hatch cover 10 is facilitated by means ofwheels or rollers 30 respectively mounted adjacent the ends of sections14 and 16. Wheels 30 are adapted to roll on tracks 32 provided oncoaming 22. Tracks 32 have inclined portions 36 to facilitate theclosing of hatch cover 10 through the operation of gravity thereon. Asshown in FIG. 1, when hatch cover 10 is closed, wheels 30 mounted onsection 16 are displaced laterally with respect to wheels 30 mounted onsection 14.

A pair of retractable hatch cover operating rigs 38 and 38 are providedfor opening and closing the halves of hatch cover 10. As shown moreclearly in FIGS. 3 and 4, rig 38 comprises a boom 40 pivotally mountedat one end to the coaming of barge 26 by means of mounting bracket 42.Bracket 42 is mounted intermediate energy accumulator devices 28.Secured to the free end of boom 40 is a linkage 44 comprising rope 46and bar 48. One end of rope 46 is secured to pin 50 positioned at theend of boom 40. The other end of rope 46 is secured to pin 52 mounted atthe free end of bar 48. The other end of bar 48, in turn, is rotatablysecured to member 54 of section 12.

As shown in FIGS. 1 and 4, section 12 is provided with a slot 56. Whenrig 38 is in its retracted position, boom 40 and linkage 44 rest withinslot 56 below the upper surface of section 12. Supporting member 58mounted on member 60 of section 12 supports boom 40 in the re-- tractedposition. As shown in FIG. 4, the height of mount ing bracket 42 ispreferably substantially equal to or less than the height of hatch cover10, so that no portion of bracket 42 protrudes above the plane of theupper surface of cover 10.

A winch 62 mounted on collapsible winch supporting fixture 64 isprovided with a rope 66, the end of which is secured to pin 68 mountedabove pin 50 on the free end of boom 40. In the retracted position, theend of rope 66 lies within slot 56 of section 12.

Fixture 64 comprises members 70 and 72 pivotally mounted at their lowerends to the deck of barge 26, winch 62 being mounted at the end ofmember 70. When rig 38 is in the retracted position, member 70 issecured to the lower portion of member 72 so that winch 62 does notprotrude above the plane of the upper surface of hatch cover (see FIG.2). When rig 38 is in the extended position, however, member 70 ispinned to the upper portion of member 72 to facilitate operation ofwinch 62.

Operation of rig 38 in opening hatch cover 10 is as follows: When hatchcover 10 is closed, rig 38 is retracted with boom 40 and linkage 44lying within slot 56. Fixture 64 is likewise retracted such that noportion of rig 38 projects above the upper plane of hatch cover 10. Whenit is desired to open hatch cover 10, fixture 64 is extended to raisewinch 62. Winch 62 is then operated either manually or automatically toreel in rope 66, thereby to raise boom 40 and make taut linkage 44. Thisis shown more clearly on the right-hand side of FIG. 3, wherein hatchcover 10 is closed, but rig 38' has been extended.

Further operation of winch 62 to reel in rope 66 causes boom 40 torotate, said rotation of boom 40 causing rotation of section 12 by meansof linkage 44. Due to the hinged interconnection between sections 12 and14, rotation of section 12 causes the hinged end of section 14 to belifted, thereby to cause section 14 to be folded upon section 12 in asubstantially vertical position. The free end of section 14 rolls alongtracks 32, thereby facilitating the folding of hatch cover 10 out of theway of the hatchway of barge 26.

Chains 74 are provided to limit the rotation of section 12, chains 74being secured at one of their ends to section 12 and at the other oftheir ends to the deck of barge 26. Latches 76, pivotally mounted onsection 14, are adapted to latch on to latching pins 78 on section 12when sections 12, 14 are in the stowed or open position. Latches 76prevent closing of sections 12, 14.

Closing of hatch cover sections 12 and 14 is accomplished by firstunlatching latches 76 from pins 78 and unreeling rope 66 through theoperation of winch 62. Through the action of gravity, the weight ofsections 12 and 14 causes section 14 to roll down inclined portions 36of tracks 32. Further unreeling of winch 62 causes sections 12 and 14 tobe extended to the closed position and thereafter lowering of linkage 44and boom 40 into slot 56. Fixture 64 is then separately retracted,thereby completing the stowing of rig 38.

Energy accumulator devices 28 are preferably provided to reduce themechanical power required of winch 62 to raise hatch cover 10. Referringmore particularly to FIGS. 5, 6, and 7, section 12 is pivotally mountedon coaming 22 of barge 26 by means of arms 24 rigidly connected to therear edge of section 12, mounting brackets 27 rigidly connected tocoaming 22, and pivot pins 84 passing through bores in arms 24 andbrackets 27. A torsion spring 86 is rigidly connected at one end to anarm 24 by means of socket 88 provided on arm 24. Spring 86 is rigidlymounted at its other end in a mounting bracket 90 comprising socket 92,and support member 94 mounted on coaming 22.

As shown more clearly in FIG. 6, torsion spring 86 comprises a pluralityof flat strips or blades 96 assembled along their major faces in orderto constitute a bundle of substantially rectangular and preferablysquare cross-section. As shown, six blades 96 comprise spring 86.However, it will be understood that any appropriate number may be used.The end of spring 86 is secured in socket 92 by means of four wedgingblocks or like elements 98 disposed within socket 92. The other end ofspring 86 may be mounted in socket 88 in similar manner.

As shown, torsion spring 86 is axially aligned with the pivotal axis ofsection 12. Spring 86 is so mounted with respect to section 12, as to befree of any torsional torque when cover 10 is stowed in the openposition (in the position shown at the left of FIG. 3). When sections12, 14 are moved to the closed position, torsion spring 86 is twistedthrough an angle of about 90 by the weight of said sections. The torquethus accumulated in spring 86 is subsequently available for mechanicallyassisting winch 62 during the next opening of cover 10. This mechanicalassist provided by spring 86 reduces the mechanical power required fromwinch 62 in opening cover 10.

As shown in FIG. 1, a pair of energy accumulator devices 28 are providedfor each half of cover 10, an individual device 28 being provided foreach pivotal connection of a section of cover 10 to coaming 22 of barge26. Each accumulator device 28 is preferably substantial ly identical tothat described hereinabove with respect to FIGS. 5, 6, and 7, and isconnected to an appropriate section of cover 10 in similar manner.

As is also shown in FIG. 1, a separate rig 38 is provided for each halfof cover 10. Although rig 38 has been described hereinabove moreparticularly with respect to sections 12 and 14, it will be understoodthat rig 38' associated with sections 16 and 18 is preferablysubstantially identical in structure and operation.

Dogs 100 provided along the edges of the sections of cover 10 areadapted to be acted upon by closing devices (not shown) which maintaincover in the closed position during transit.

Referring now to FIGURES 8-10, there is shown another embodiment of theretractable rig of the present invention. According to this embodiment,a retractable rig 110 is provided comprising a boom 112 and linkage 114.As described hereinabove, boom 112 is preferably pivotally mounted on abracket 115 substantially midway the width of hatch cover 10. Boom 112comprises members 116 and 118, member 116 being pivotally connected tomember 118 by pin 120. The other end of member 118 is pivotallyconnected to bracket 115 by pin 122. As will be described in greaterdetail hereinafter, the pivotal axis A of member 118 about bracket 115is positioned above the pivotal axis B of hatch cover section 12 aboutbrackets 27.

A sheave or pulley 124 is pivotally connected at the free end of member116 of boom 112 by means of pin 126. An idler pulley 128 is pivotallymounted on boom memher 116 below sheave 124. Rope 66, wound about winch64, is passed around sheave 124 and anchored to the deck of barge 26 bymeans of bar 130, which is secured at one end to the free end of rope 66and pivotally mounted at the other end to the deck of barge 26.

Linkage 114 comprises members 136, 138, and 140, and is connectedbetween the free end of boom member 116 and member 134 of batch coversection 12. Member 136 is comprised of a pair of parallelly arrangedmembers 136a and 136b. Members 136a and 136b are pivotally connected atone end to the free end of boom 112 and at the other end to linkagemember 138. In like manner, linkage member 140 comprises a pair ofparallelly arranged members 140a and 140b, which are pivotally connectedat one end to member 138, and at the other end to member 134 of batchcover section 12. As shown more particularly in FIGS. 9 and 10, members136 and 138 are spaced apart by a distance somewhat greater than thethickness of member 138, such that when rig 110 is in the retractedposition, stowed within hatch cover section 12, member 138 willtelescope partially into member 136, In similar manner, members 140a and14017 are spaced apart for a portion of their length a suflicientdistance to permit telescoping of member 138, as well as member 136thereinto, when rig 110 is retracted.

A pair of locking studs 142 and 144 are provided on boom member 116 anda pair of complementary locking studs 146 and 148 are provided withinchannel 150 of hatch cover section 12. Studs 142 and 144 arerespectively spaced horizontally from studs 146 and 148 and as will bedescribed in greater detail hereinafter, studs 142 and 144 will engagestuds 146 and 148 when hatch cover sections 12 and 14 are raised to anopen position by external means, thereby securing rig 110 within section12.

Mounted on the deck of barge 26 is a support 152. Support 152 ispositioned at the pivotal connection of boom members 116 and 118, and isadapted to support member 118 in a substantially horizontal position, aswell as to provide a pivot point for member 116 when rig 110 is extendedto open hatch cover sections 12 and 14.

In operation, reel 64 is cranked to reel in rope 66. By having rope 66passed over sheave 124, and anchored to the deck of barge 126, themechanical advantage of the rig is increased over the rig describedhereinabove and shown in FIGURES 1-4, where rope 66 was merely attachedto the end of the boom. In the arrangement shown, the advantage isincreased twofold. The mechanical advantage may be increased evenfurther by using additional sheaves which are mounted on the boom and/orthe deck, and about which rope 66 is passed. For example, if anadditional sheave is secured to the barge deck and rope 66 is passedabout sheave 124, about the additional sheave secured to the deck, :andthe end of the rope is secured to the boom, the mechanical advantagewill be increased three-fold. In this manner, heavier hatch covers maybe raised with no increase in force applied to the winch.

As described hereinabove, rope 66 passes over idler pulley 128 when rigis retracted. As rope 66 is reeled in, thus causing member 116 to pivoton support 152, the angle formed between rope 66 and member 116 willincrease, until the point is reached where rope 66 will no longer be incontact with idler pulley 128. This point will be reached before hatchcover section 12 is caused to be lifted, so that during the liftingoperation, rope 66 will be substantially linear between reel 64 andsheave 124.

As member 116 is caused to pivot, linkage 114 is extended, until suchpoint when members 136, 138, and are aligned. At this point (seeright-hand side of FIG. 8) linkage 114 is fully extended and furtherrotation of member 116 acts to raise cover section 12 by means oflinkage 114.

Member 116 is rotated until sections 12 and 14 are substantiallyvertical and have reached the open position (see left-hand side of FIG.8). As described hereinabove, chains 74 are provided to limit thefurther rotation of section 12, and latches 76 pivotally mounted onsection 14 are adapted to latch onto latching pins 78 on section 12 toprevent closing of sections 12 and 14.

When it is desired to close sections 12 and 14, latches 76 aredisengaged from pins 78, and rope 66 is unreele Through the action ofgravity, the weight of sections 12 and 14 causes section 14 to roll downinclined portions 36 of tracks 32. After sections 12 and 14 have beenextended to the closed position, further unreeling of rope 66 causeslinkage 114 to telescope into channel of section 12, and to cause boommember 116 to also telescope into channel 150. As described hereinabove,energy accumulator means 28 are preferably provided to reduce themechanical power required of Winch 64 to raise hatch cover 10.

By shifting the effective pivot point of the boom, i.e., the pivot pointof boom member 116, forward of the pivot point of the hatch cover,increased mechanical advantage is obtained, thus further reducing theforce of the winch required to open the hatch cover.

As described hereinabove, external means such as a dockside crane may beprovided to open hatch cover 10. In such cases, it is desirable that rig110 be retained within slot 150 of section 12 when the cover is fullyopened. Due to the tendency of member 116 to fall out of slot 150 whensection 12 is in a vertical position, locking studs 142, 144, 146, and148 are provided, and the pivotal axis of member 118 is displaced abovethe pivotal axis of the hatch cover. As cover 12 is rotated, the weightof member 116 will maintain it in channel 150, and will cause member 116to remain substantially linearly aligned with member 118 and to pivotabout bracket 115. However, as cover 12 is raised, there will be arelative sliding movement between boom member 116 and the hatch coversection, so that locking studs 142 and 144 slide under studs 146 and148. When cover 12 is raised to its full vertical position, lockingstuds 142 and 144 will have reached the positions shown in dotted linesin FIG. 9 and will be substantially opposite studs 146 and 148. Thusboom 112 will be locked within cover section 12.

Although preferred embodiments of the rig of this invention have beenshown and described hereinabove, it will be understood thatmodifications thereof within the knowledge of those skilled in the artmay be made and are still considered to be within the scope of thepresent invention. Thus, although the boom (40, 112) has been shownpivotally mounted on coaming 22 midway of section 12, the boom may alsobe mounted anywhere along the lateral width of coaming 22 with thelinkage (44, 114) suitably connected to section 12. Moreover, it is notrequired that boom 40 be mounted on coaming 22 substantially at thepivotal axis of section 12. Thus boom 40 could also be mounted behindcoaming 22 on the edge of barge 26. In like manner, although the boomand linkage have been shown and described as retracting into a slotformed in section 12 in order to dispose them below the surface of coverto provide a minimum of height of barge 26, it will be understood thatwhere height limitations are not as critical, the boom and linkage couldalso rest on the upper surface of cover 10, thus obviating the necessityfor a slot in section 12. Although only a single boom and linkageassembly has been shown and described as associated with each hatchcover half, two or more boom and linkage assemblies operatedindividually or in tandem may also be provided in place thereof.

It will also be understood that although linkage 44 has been shown anddescribed as comprising a rope and bar connected together, bar 48 couldbe eliminated, with a single rope, chain or the like, extending betweenboom 40 and section 12. In such a case, it is desirable that some meansbe provided to cause the rope to fall into slot 56 when boom 40 islowered thereinto. Such rope slackening means are well known in the art,and could, for example, be a guide rope. Similarly, linkage 114 maycomprise more or less than the three members shown in FIGS. 8-40. Inthis application, the term linkage is meant to refer to any means suchas ropes, chains, etc., for connecting the boom to the hatch coversection.

Although a specific form of mounting fixture for winch 62 has beendescribed and shown, it will be understood that any suitable mountingfixture could be provided, and still be considered within the presentinvention. Although it is desirable that the mounting fixture for winch62 be collapsible, this is not required and a fixture rigidly mountingwinch 62 to barge 26 may be used. It will also be understood that winch62 may be operated manually or operated automatically by means of asuitable power drive.

Although the rig has been described as associated with an energyaccumulator device, it will be understood that rig 38 may be operablewithout such a device. In such case, it is only necessary that the powerof winch 62 be increased to make up for the mechanical advantageprovided by device 28. Although a specific form of device 28 has beendescribed, other forms and modifications known to those skilled in theart may be substituted therefor. It is only necessary that such a deviceprovide mechanical assist in opening the hatch cover 10. Other forms ofsuch device are, for example, described in copending US. applicationS.N. 346,279 for Closing Device For Hatch Covers and the Like now US.Patent No. 3,389,739.

The retractable rig of the present invention may be used with hatchcovers which are either weather-tight or water-tight when closed.

Although a preferred embodiment of the present invention has beendescribed hereinabove and shown in the drawings, it will be understoodthat modifications thereto and other embodiments evident to thoseskilled in the art are also considered to be within the presentinvention. Therefore, the scope of this invention should be determinedfrom the following claims taken in the light of said description anddrawings.

What is claimed is:

1. In a vessel having a deck, a hatch in said deck and a hatch coverhaving at least one section pivotally mounted at the edge of the hatch,the improvement comprising a retractable rig comprising a retractableboom assembly connected to said hatch cover section and adapted to beretracted when not in use and a retractable winch assembly to operatesaid hatch cover, said winch assembly being mounted on a retractablefixture which is adapted to be retracted when not in use.

2. The retractable rig of claim 1 including energy accumulator meansassociated with said rig and connected to said hatch cover section insuch manner as to mechanically assist the opening of said hatch cover.

3. The retractable rig of claim 1 including drive means connected tosaid winch assembly for driving said assembly.

4. In a vessel having a deck, a hatch in said deck and a hatch coverhaving at least one section pivotally mounted at the edge of the hatch,the improvement comprising a retractable rig comprising boom pivotallymounted near the rear of said hatch cover section, a first linkageconnected between said boom and said hatch cover section, a Winch and asecond linkage Wound up on said winch and connected to said boom, saidwinch being mounted on a retractable fixture mounted on said deck to therear of said boom, said boom and first linkage being adapted to beretracted to a substantially horizontal position when not in use andsaid fixture being adapted to be retracted when not in use.

5. The retractable rig of claim 4 wherein said boom is mountedsubstantially midway the width of said hatch cover section and saidlinkage is connected to said hatch cover section substantially at theedge opposite said pivotally mounted edge, substantially midway thewidth thereof.

6. The retractable rig of claim 4 wherein said first linkage comprises arope and bar assembly.

7. The retractable rig of claim 4 wherein said first linkage comprises aplurality of members connected together.

8. The retractable rig of claim 4 including an energy accumulator deviceassociated with said rig and connected to said hatch cover section insuch manner as to mechanically assist the opening of said hatch cover bysaid rig.

9. The retractable rig of claim 4 wherein said boom comprises first andsecond members respectively having first and second ends, said membersbeing pivotally connected together at their respective first ends, andincluding a support mounted to the front of the pivotal axis of saidhatch cover section, said first end of said first member resting on saidsupport, said support providing a pivot point for said second memberwhen said boom is extended.

10. The rig of claim 9 wherein said second end of said first member ofsaid boom is pivotally mounted and has a pivotal axis above the pivotalaxis of said hatch cover section, but in the same vertical planethereas.

11. In a vessel having a deck and a hatch in said deck the improvementcomprising a hatch cover assembly having at least one hatch coversection pivotally mounted at the edge of said hatch, a boom pivotallymounted near the rear of said section, a first linkage connected betweensaid boom and said hatch cover section, a winch, a retractable fixturemounted on said deck, said winch being mounted on said fixture, a secondlinkage wound up on said winch and connected to said boom, said boom andfirst linkage being adapted to be retracted to a substantiallyhorizontal position when not in use and said winch and fixture beingadapted to be retracted when not in use.

12. The hatch cover assembly of claim 11 including an energy accumulatordevice mounted on said deck and connected to said hatch cover section insuch manner as to mechanically assist the opening of said hatch cover bysaid rig.

13. The hatch cover assembly of claim 11 wherein said hatch coversection is provided with a slot and said boom and said first linkage areadapted to be retracted into said slot when not in use.

14. The hatch cover assembly of claim 11 including drive means connectedto said winch for driving said winch.

15. The hatch cover assembly of claim 11 wherein the pivotal axis ofsaid boom is coaxial with the pivotal axis of said pivotally mountedhatch cover section.

16. The hatch cover assembly of claim 11 wherein the pivotal axis ofsaid boom is forward of the pivotal axis of said hatch cover section.

17. The hatch cover assembly of claim 13 wherein the pivotal axis ofsaid boom is above the pivotal axis of said hatch cover section andwherein said boom is provided with locking means and said hatch coversection is provided with complementary locking means positioned withinsaid slot adjacent said boom locking means, such that when said hatchcover section is opened by external means, said boom will slide withinsaid hatch cover section to cause said boom locking means to engage saidhatch cover section locking means to maintain said boom and linkage insaid hatch cover section in the open position.

18. The batch cover assembly of claim 11 wherein said boom comprisesfirst and second members respectively having first and second ends, saidmembers being connected together at their respective first ends andincluding a support mounted on said deck to the front of the pivotalaxis of said hatch cover section, said first end of said first memberresting on said support, said support providing a pivot point for saidsecond member when said boom is extended.

References Cited UNITED STATES PATENTS Frey 160-193 Brazier et a1 49347Whittelsey 114-201 X Frost 141 Honey 52-119 X Floehr 105-377 Stransky160188 X Dahlin 160-193 Learmont 21477 Kummerman et al. 160188 US. Cl.X.R.

